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2018 Vol.35(7)

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2018, 12(7): 1592-1592.
[Abstract](624) [PDF 1103KB](25)
Orginal Article
Influence of the density of burrow entrances of plateau pika on the concentration of soil nutrients in a Kobresia pygmaea meadow
Wen-na Zhang, Shao-hong Jin, Cheng Yu, Xiao-pan Pang, Juan Wang, Zheng-gang Guo
2018, 12(7): 1593-1601. doi: 10.11829/j.issn.1001-0629.2018-0215
[Abstract](1017) [FullText HTML] (114) [PDF 1676KB](74)
Disturbance in the population of the plateau pika, Ochotona curzoniae, often induces changes in the concentration of soil nutrients in alpine meadows. The effects of disturbance in the population of plateau pika on the concentration of the primary soil nutrients in a Kobresia pygmaea meadow was investigated to examine the relationships between the density of total burrow entrances and active burrow entrances of plateau pika and the concentration of the primary soil nutrients. Our results showed that the disturbance significantly increased the concentration of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), soil ammonium nitrogen (NH4+-N), and nitrate nitrogen (NO3--N) in the soil, but there was a decrease in available phosphorus (AP) concentration in the 0-20 cm soil layer. As the densities of total burrow entrances and active burrow entrances increased, the total nutrient concentration in the 0-20 cm soil layer (SOC, TN, and TP) initially increased but then decreased. The nutrient concentration for NH4+-N, NO3--N, and AP initially decreased then increased, indicating the relationship between the density of total burrow entrances and the concentration of soil nutrients are consistent with the density of active burrow entrances of plateau pika and the concentration of soil nutrients. Therefore, when determining the effects of plateau pika disturbances on the concentration of soil nutrients, the density of active burrow entrances can be replaced with the density of total burrow entrances.
Spatio-temporal change in water and thermal climatic conditions during the green grass season in the Urumqi area from 1961 to 2016
Zong-chao Pu, Shan-qing Zhang, Wahati, Ke Wang, Habulahati, Shalamu, Li-ye Feng, Liang Chen, Yi-cheng Ge, Maimaiti
2018, 12(7): 1602-1613. doi: 10.11829/j.issn.1001-0629.2017-0452
[Abstract](969) [FullText HTML] (144) [PDF 3737KB](29)
The fundamental spatio-temporal change characteristics of the start and end dates, duration, average temperature, accumulated temperature of ≥5 ℃, precipitation, and arid-wet index of the green grass season were analyzed by using linear regression and mixed spatial interpolation technology based on ArcGIS, using the daily meteorological data collected from 10 meteorological stations in Urumqi City and its surroundings area from 1961 to 2016. The first and last dates when the daily mean temperature were stably ≥5 ℃ in a year were taken as the start date and end date of the growth of natural pasture and the green grass season, respectively. The main results showed that the spatial distribution of the above-mentioned climate factors were clearly varied among several observed locations in the Urumqi area. Generally, the start dates of the green grass season were earlier in the plain desert pastures than on the mountain grasslands and meadows. However, the end dates of the green grass season were later on the plain desert pastures than on the mountain grasslands and meadows. Several thermal elements, such as duration, average temperature and ≥5 ℃ accumulated temperature of green grass season were higher on the plain desert pastures than on the mountain grasslands and meadows. Precipitation in the green grass season was higher on the mountain grasslands and meadows than on the alpine meadows and plain desert pastures. The arid-wet index of the green grass season increased with altitude. In the past 56 years, the start dates of the green grass season had shown an inconspicuous (P>0.05) advancement at the rate of -0.424 d·10 a-1, and the end dates have been significantly (P<0.01) delayed, at the rate of 1.455 d·10 a-1. At the same time, the duration, average temperature, accumulated temperature of ≥5 ℃, precipitation, and arid-wet index of the green grass season significantly (P<0.05) increased at the rate of 1.879 d·10 a-1, 0.16 ℃·10 a-1, 61.14 (℃·d)·10 a-1, 6.93 and 0.015 mm·10 a-1, respectively. However, these changes had regional differences. Comparing the last 30 a (1961-1990) with the most recent 26 a (1991-2016) the earlier days of the start of the green grass season showed little regional difference, and a greater increase in the delayed days of the green grass end dates, green grass season duration, average temperature, accumulated temperature of ≥5 ℃ was observed on the plain desert pastures than on the mountain grassland and meadow, but the increments of precipitation and arid-wet index of the green grass season were greater on the mountain grasslands and meadows than on the plain desert pastures in the Urumqi City.
Analysis of functional differences among three Medicago sativa endophytic rhizobial strains
Wen-juan Kang, Shang-li Shi, Ze-yi Wang, Jian-gang Chen, Yang-yang Miao
2018, 12(7): 1614-1623. doi: 10.11829/j.issn.1001-0629.2017-0390
[Abstract](845) [FullText HTML] (104) [PDF 1451KB](27)
Three endophytic rhizobial strains (Sinirhizobium meliloti, LP3, WLP2, and WLG1) were inoculated onto Medicago sativa ‘WL168HQ' grown on sterilized sand in glass test tubes to analyze their symbiotic ability. The control was treated with cultural liquid without rhizobial strains. Strains were also studied to evaluate stress tolerance and growth promotion. Results showed that endophytic rhizobial strain WLP2 could tolerate all tested antibiotics (≥ 300 μg·mL-1) except for erythromycin and gentamycin. It could grow in a medium containing 6% NaCl and with pH 5~11, and could tolerate a temperature range of 8~40 ℃. This strain was able to dissolve organic phosphate (EYPC) and inorganic phosphate [Ca3(PO4)2], and was capable of secreting indole acetic acid as well. The symbiotic effects of strain WLG1 were optimal. The nodule numbers, along with above-ground and below-ground dry weight of plants inoculated with WLG1, increased significantly (P<0.05) compared with the control, with increases of 208.16%, 72.35%, and 122.33%, respectively. Effective nodule weight, root length, and leaf number of plants inoculated with WLG1 increased by 6.68%, 9.57%, and 53.59% compared with the control, respectively. Altogether, endophytic rhizobial strain WLP2 presented high antibiotic, salt, pH, and temperature resistance and had a strong ability to promote plant growth, while strain WLG1 showed better inoculation effects on M. sativa ‘WL168HQ' and strong symbiotic nitrogen fixation.
The isolation and identification of endophytic actinobacteria from Glycyrrhiza glabra in the Tarim basin and their stress resistance and ability to promote plant growth
Mei-ling Shen, Chong Zhao, Ping Liao, Jing Li, Xue-fen Cheng, Cheng-cheng Li, Qin Zhang, Yan-bin Li, Li-li Zhang, Ke Zhao
2018, 12(7): 1624-1633. doi: 10.11829/j.issn.1001-0629.2017-0374
[Abstract](783) [FullText HTML] (76) [PDF 1741KB](19)
Endophytic actinobacteria isolated from roots, stems, and leaves of Glycyrrhiza glabra in the Tarim basin, Xinjiang were analyzed for diversity, stress resistance, and ability to promote plant growth activity. A total of 124 endophytic actinobacteria were isolated from 8 media. Based on traditional morphological observation, 32 representative strains were selected for 16S rRNA sequencing. According to the phylogenetic analysis, all of the strains belonged to Streptomyces sp. Subsequently, stress resistance and the ability to promote plant growth activity were evaluated. The results showed that the salt tolerance of strains decreased with increasing salt concentration, and 6.3% of the strains were able to tolerate 15% NaCl concentrations. All of the strains were able to grow on media of pH 7.0; however, only 3.1% could grow on media of pH 5.0 and pH 11.0, respectively. With a polyethylene glycol (PEG) concentration of 25%, the growth rate of strains decreased to 56.3%. When the PEG concentration reached 35%, strains were unable to grow normally. Moreover, 65.6% of the strains could produce indole-3-acetic acid, 50% of the strains had the ability to produce siderophores, and 25% of the strains were able to dissolve phosphorus. The results showed that Streptomyces sp. was the dominant genera of endophytic actinobacteria, and not only possessed strong resistance, but also had plant growth-promoting activity.
Effects of grazing on soil microbial and biomass enzyme activities in Wugong Mountain, China
Xiao-feng Xu, De-kui Niu, Xiao-min Guo, Bang-liang Deng, Gui-xiang Zhou, Shu-li Wang, Cong-fei Zhu, Han-dong Luo
2018, 12(7): 1634-1640. doi: 10.11829/j.issn.1001-0629.2017-0629
[Abstract](742) [FullText HTML] (103) [PDF 1354KB](27)
To understand the effects of different grazing intensities on soil microbial biomass carbon and nitrogen and enzyme activities in Wugong Mountain meadow, we conducted a study to provide a theoretical basis for the restoration of degraded meadow. The results showed that the contents of soil microbial biomass carbon and nitrogen in the 0-20 cm soil layer were higher than that in the 20-40 cm soil layer. In addition, with increased grazing intensity, the contents of microbial biomass carbon and nitrogen were decreased significantly (P<0.05); however, there was no significant difference in the contents of microbial biomass nitrogen (P>0.05) between light and moderate grazing in the 20-40 cm soil layer. The contents of dissolved organic carbon and nitrogen were not significantly different in the 0-20 and 20-40 cm soil layers (P>0.05). The contents of dissolved organic carbon and nitrogen with light grazing were higher than those with moderate and high grazing treatments in the 0-20 cm soil layer (P<0.05). The contents of alkaline nitrogen and readily oxidizable carbon with light grazing were significantly higher than contents with moderate and high grazing in the 0-20 and 20-40 cm soil layers (P<0.05). Soil β-glucosidase, β-N-acetylglucosaminoglycan, and urease activity were significantly higher with light and moderate grazing than with high grazing in the 0-20 and 20-40 cm soil layers (P<0.05). Correlation analysis showed that the activities of soil β-glucosidase, β-N-acetylglucosaminidase, and urease were positively correlated with microbial biomass carbon and nitrogen at all grazing intensities (P<0.05 or P<0.01).
Effect of silicon supplies on biomass and antioxidase and osmolytes of tall fescue seedlings under different salt concentration conditions
Xuan-dong Lin, Wen-Li Wu, Li-guo Lin, Yu-pei Zhou, Hui-Xia Liu
2018, 12(7): 1653-1660. doi: 10.11829/j.issn.1001-0629.2017-0382
[Abstract](836) [FullText HTML] (59) [PDF 1321KB](30)
In this study, a pot experiment was conducted to determine the response of biomass, antioxidant enzyme activities, and osmotic regulators to silicon in tall fescue seedlings under different salt stress condition. The results showed that with an increase in salt concentration, the biomass of tall fescue decreased gradually. When the salt concentration was less than 50 mmol·L-1 or greater than 250 mmol·L-1, silicon had no obvious effect on the biomass of tall fescue; when the salt concentration was between 50 and 250 mmol·L-1, the biomass of tall fescue increased significantly (P<0.05) with silicon. With an increase in salt concentration, CAT activity increased, and POD and SOD first increased and then decreased. Although the addition of silicon increased the activity of POD, SOD, and CAT, there are some differences in the salt concentrations when the different enzymes increased significantly. With an increase in salt concentration, MDA content increased, soluble sugar and soluble protein content first increased and then decreased, and when the salt concentration reached 200 and 250 mmol·L-1, soluble sugar and soluble protein contents reached their highest values. The addition of silicon reduced the contents of soluble sugar, soluble protein, and MDA in tall fescue. The above results showed that the effect of silicon on the salt tolerance of tall fescue varied under different salt stresses. When the salt concentration was too low or too high, the silicon had no significant effect on the adaptability of tall fescue, but when the salt concentration was in a middle range, the silicon enhanced the adaptability to salt stress of tall fescue by increasing the antioxidant enzyme activity in the plants, improving the osmotic adjustment process and reducing membrane oxidation.
Effect of environmental factors on seed germination of Limonium aureum
Jing-jing Wang, Ling Yu, Gong Zhu, Xiang-lai Chen, Xiao-wen Hu
2018, 12(7): 1661-1669. doi: 10.11829/j.issn.1001-0629.2017-0474
[Abstract](785) [FullText HTML] (100) [PDF 1371KB](29)
The effect of temperature, light, water, salt, and burial depth on seed germination of Limonium aureum was analyzed. The results indicated that: 1) Temperature, light and their interaction significantly affected L. aureum seed germination (P<0.001). Germination percentage and germination rate increased initially and then decreased with increasing temperature, and reached the highest when the temperature was 25, 30, and 20/30 ℃. When the temperature was 35 and 40 ℃, light promoted seed germination of L. aureum significantly (P<0.05), whereas light showed no effect at other temperatures (P>0.05); 2) With increasing drought and salt stress, germination percentage and germination rate of L. aureum decreased gradually. The median lethal concentrations of drought resistance and salt tolerance for L. aureum were -0.64 and -0.84 MPa (0.201 mol·L-1), respectively. When osmotic potential was low, seeds under salt stress germinated better than those under drought stress; 3) The optimal sowing depth of L. aureum seeds was 0.5 cm.; therefore, these seeds are possibly suitable for shallow seedling.
Growth response of Praxelis clematidea seedlings to water and nitrogen coupling
Jun-di Zhong, Xiao-yun Mo, Jin-xiang Liu
2018, 12(7): 1670-1678. doi: 10.11829/j.issn.1001-0629.2018-0043
[Abstract](806) [FullText HTML] (114) [PDF 1383KB](16)
The response mechanism of invasive species of Praxelis clematidea seedling growth to different water and nitrogen (WN) coupling models were investigated by determining the relationship between WN and bio-invasion. This experiment incorporated three irrigation levels and four levels of nitrogen, for a total of 12 processes to study the coupling effect of different WN processing on P. clematidea parameters including morphological, biomass and chlorophyll content. P. clematidea seedlings were significantly affected by the WN coupling (P<0.05). The seedlings grew better with higher root, stem and leaf morphological indexes, such as plant height, stem diameter, leaf area, total root length and root surface area, and more biomass accumulation under suitable moisture and nutrient conditions, such as treatment with the intermediate level of WN (saturated sand water content 60%~70%, water supply 60 mL·kg-1, nitrogen supply 0.30 g·kg-1). P. clematidea seedlings exposed to each nitrogen treatment coupled with low level of water (saturated sand water content 30%~40%, water supply 30 mL·kg-1) or high level of water (saturated sand water content 90%~100%, water supply 90 mL·kg-1) displayed lower root, stem and leaf morphological indexes and less biomass accumulation than the corresponding nitrogen treatment coupled with the intermediate level of water. Leaf chlorophyll content of P. clematidea was more sensitive to nitrogen, which increased with the increase of nitrogen. We can draw the conclusion that P. clematidea easily invades an environment with a certain content of WN, but has more restricted distribution in an environment with excessive or insufficient water or nutrients, which is closely related to its invasion.
Effect of cadmium stress on growth, absorption, and accumulation in green manure “Chafei 1#”
Fen Xiang, Wei Li, Hong-yan Liu, Ling-yun Zhou, Ding Ding, Zhen Zeng
2018, 12(7): 1679-1684. doi: 10.11829/j.issn.1001-0629.2017-0439
[Abstract](750) [FullText HTML] (64) [PDF 1281KB](17)
The growth, absorption, and accumulation of Chafei 1# (Cassia sophera) under different cadmium (Cd) concentrations (0, 5, 10, 20, 40, 80, 120, 160 mg·kg-1) were investigated using the pot experiment. The results showed that upon adding 0~160 mg·kg-1 Cd in soil, the growth of various organs were significantly inhibited along with increasing concentrations of Cd. There were significant positive correlations between Cd content in organs and Cd stress, and Cd content in organs and available Cd content (P<0.05). The order of Cd content in various organs was root>stem>leaf; in addition, most of the Cd was fixed by the roots in the soil, so less Cd was transported from the soil to the upper part, indicating that the roots of Chafei 1# were vulnerable to Cd toxicity. Although the Chafei 1# was treated with a high concentration of Cd, in a short time, there was an obvious enrichment in Cd as Cd stress increased, as the content in the root, stem, and leaf were 113.85, 20.15, and 7.0 mg·kg-1, respectively. Therefore, Chafei 1# could be planted in polluted areas as soil remediation plants, which are of great significance to environmental protection and in control measures for polluted cultivated land.
Cloning and prokaryotic expression of the glucanase gene Glu1 from Trichoderma asperellum
Gui-ping Diao, Shuai Yang, Wen-jing Yu
2018, 12(7): 1685-1694. doi: 10.11829/j.issn.1001-0629.2017-0463
[Abstract](805) [FullText HTML] (65) [PDF 3630KB](17)
A 984-bp glucanase gene (Glu1) was cloned from Trichoderma asperellum ACCC30536, and was found to encode a sequence of 327 amino acids. The Glu1 protein, which belongs to the Glyco-hydro-12 family, is predicted to be a β-1, 4-glucanase. The Glu1 amino acid sequence has 91% identity and the closest relationship with the Glyco-hydro-12 family protein XP_013940397.1 of T. atroviride IMI 206040. Using qRT-PCR analysis, Glu1 expression levels in T. asperellum were monitored under nine different induction conditions, which indicated that Glu1 may participate in the recognition between T. asperellum and poplar or poplar fungal phytopathogens. A prokaryotic expression vector was successfully constructed and a recombinant protein rGlu1 was obtained. Enzyme activity analysis indicated that the optimum pH and temperature for rGlu1 activity is 4.5 and 45 ℃, respectively, and that rGlu1 activity gradually increases with a prolongation of induction duration up to 5 h.
Evaluating the genetic diversity of Festuca sinensis germplasm resources in the Qinghai-Tibetan Plateau by EST-SSR markers
Li-ying Xu, Qing-ping Zhou, Shi-yong Chen, You-jun Chen, Ya-ping Li, Li-hua Tian
2018, 12(7): 1695-1703. doi: 10.11829/j.issn.1001-0629.2018-0037
[Abstract](732) [FullText HTML] (56) [PDF 1472KB](21)
In this study, EST-SSR markers were used to study the genetic diversity and genetic relationship of 24 Festuca sinensis germplasms from Sichuan, Tibet and Qinghai. There were 102 loci detected from 17 primers and 5~8 loci per polymorphic locus. The mean number of polymorphic loci was 6 and the mean percentage of polymorphic loci was 93%. The range of genetic similarities was 0.188~0.675, with an average of 0.486, and polymorphism information content was 0.381, ranging from 0.240 to 0.470, which also revealed that the genetic resources of F. sinensis were rich in genetic diversity. The results of cluster analysis and principal component analysis showed that the association between the genetic relationships and geographical origin was low. Among them, the I-2-23-7and I-14-1-1 showed genetic specificity. The test materials were highly dissimilar between the 24 F. sinensis germplasms. Analysis of geographical elevations revealed that the F. sinensis germplasms with medium altitude (3 000-3 500 m) displayed the highest Nei's gene diversity (0.304 3) and Shannon's diversity index of 0.462 2, which indicated high genetic variation. The results provide an important reference for the conservation and utilization of the F. sinensis germplasm resources in the Qinghai-Tibet Plateau.
Effect of elevated CO2 level on the anatomical structure of Medicago sativa, under different fall dormancy types
Le-shan Du, Hai-yan Liu, Xiao-meng Zhai, Meng-yun Ren, Jun-sheng Li, Xiao Guan
2018, 12(7): 1704-1712. doi: 10.11829/j.issn.1001-0629.2017-0442
[Abstract](697) [FullText HTML] (64) [PDF 1505KB](18)
Effect of elevated atmospheric CO2 concentration on plants has aroused wide concern among scholars. In this study, open-top chambers (OTC) were used to model the future CO2 concentration to study the effect of CO2 enrichment on the leaf anatomical structure of three types fall dormancy at different growth stages by using the paraffin section technique. Results showed that: the anatomical structure of leaves was significantly affected by the increase of CO2 concentration, the growth period, and the interaction effect of three factors. The leaf anatomical structure increased significantly with the increase of CO2 concentration (P<0.01), which was beneficial to increase chloroplast content,gas exchange rate, and subsequently the photosynthesis rate. Leaf thickness, cuticle thickness, palisade tissue thickness, and sponge tissue thickness increased significantly with the growth period (P<0.01). The anatomical structure of leaves showed no significant differences among three fall dormancy types (P>0.05), mainly because fall dormancy is influenced by the duration of light and temperature and is less affected by CO2. The results of this study provide a basis for predicting the effect of elevated CO2 on the anatomical structure of plant leaves for adaptation to CO2 concentration.
Responses of sweet sorghum under ridge culture pattern to farmland waterlogging stress
Lin-jing Tong, Tao Feng, Zheng-guo Sun, Xiao-dong Chen, Wen-xiang Yang, Jian-long Li
2018, 12(7): 1713-1719. doi: 10.11829/j.issn.1001-0629.2017-0470
[Abstract](883) [FullText HTML] (70) [PDF 1286KB](14)
Waterlogging is easily caused by common and heavy precipitation in the middle and lower reach regions of the Yangtze River in China. In this study, two culture patterns, ridge and flat, were conducted to determine the effect of culture patterns on the yield traits and antioxidant enzyme activity of sweet sorghum. The yield traits and antioxidant enzymes activity were evaluated and compared after applying waterlogging stress at the seedling stage. The results showed that when the sweet sorghum suffered waterlogging stress at the seedling stage, the stem diameter, dry weight per plant, number of leaves, and leaf area index (LAI) under the ridge culture pattern were significantly higher than those under the flat culture pattern (P<0.05). Meanwhile, the height and stem and leaf ratio of plants under ridge culture showed little differences compared to those under the flat culture pattern (P>0.05), and waterlogging stress had less impact on the antioxidant enzyme activities; SOD, POD and CAT were continually highly expressed under the ridge culture pattern. In conclusion, the experiment demonstrated that the application of ridge pattern culture improved the adaptability and yield of sweet sorghum under waterlogging stress.
Regulation of nutrient accumulation and distribution in quinoa at different growth stages
Yu-ming Wei, Fa-rong Yang, Wen-yu Liu, Jie Huang, Qian Jin
2018, 12(7): 1720-1727. doi: 10.11829/j.issn.1001-0629.2017-0638
[Abstract](1559) [FullText HTML] (396) [PDF 1365KB](33)
This study was carried out to explore the dynamic regulation of nutrient accumulation and distribution in quinoa across all growth stages, and thereby promote the efficient development and utilization of this nutritional resource. To do this, the content and transport of crude protein (CP), crude fat (EE), phosphorus (P), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in the stems, grains, leaves, roots, sheath, and whole plant were studied in the quinoa cultivar “Longli No.1”. Changes in nutrient contents and transport were compared between the seedling, flowering, filling, and mature stages of the plant's life cycle to provide a reference for the study of its nutritive value across growth stages. The results showed that dry matter accumulation dynamics in a single plant followed a slow-fast-slow pattern among the different growth stages. Differences between the output and the transfer rate of dry matter (DM) in various organs were significant (P<0.05). The maximum sheath and grain dry matter contents occurred at the filling and mature stages. The movement, output, and transport rates of dry matter were the highest in leaves, while movement and transport rates were the lowest in the roots. The contents of DM, NDF, ADF, and P showed a linear decline over the growth period. Differences in the transfer rate of nutrient matter among different organs during the growth period were in the order of leaves > sheath > stems > roots. The differences in nutrient transport among different organs in different growing periods were large, and generally were in the following order among stages: mature > flowering > filling > seedling. The order of relative feed value among plant stages were: seedling > filling > flowering > mature.
Productive performance comparison of different oat varieties in Yangzhou region
Ya Wu, Wei-hong Zhang, Ming-hui Chen, Da-lin Liu
2018, 12(7): 1728-1733. doi: 10.11829/j.issn.1001-0629.2017-0479
[Abstract](906) [FullText HTML] (130) [PDF 1261KB](23)
The aim of this study was to screen out the best oat varieties suitable for planting in the Yangzhou region. To comprehensively investigate the production performance, eight different varieties of oats were used as experimental materials. The results showed that all the oat varieties reached the heading stage during mid-April, but there were some differences among some indexes (phenology, agronomic traits, yield, and quality of forage) of different varieties of oats. At harvest stage, plant height and hay yield of Qiangshou were the highest in the experimental group. Fresh grass production of Baler, crude protein content of Xiaoma, and ether extract content of Rinne were also the highest at harvest stage. However, the differences in ether extract content among the oat varieties were highly significant. The current domestic protein yield is used as an evaluation index for the performance of herbage. The protein yield of oatmeal was 810.94 kg·ha-1, which was the highest among the tested varieties. Therefore, in terms of growth period and protein yield, Rinne has more potential for utilization in the winter fallow fields in the Yangzhou region.
Study of the effects of mixed sowing of different alfalfa varieties in the Dongting Lake area
Fei Chen, Lin Mu, Zhao-zhu Wen, Zhi-fei Zhang, Zhong-shan Wei
2018, 12(7): 1734-1742. doi: 10.11829/j.issn.1001-0629.2017-0471
[Abstract](822) [FullText HTML] (91) [PDF 1414KB](18)
In order to investigate the effects of mixed sowing of different alfalfa varieties on their yield, quality, root system, and height, a mixed sowing experiment was conducted using WL712, WL903, WL656, and WL525, which was widely cultivated in the southern region. The results showed that although the amount of crude protein of the mixed sowing alfalfa did not exceed that of the unicast WL525, which was also used in mixed sowing, it was better than that of other unicast varieties also used in mixed sowing. Although plant height showed no significant increase, fiber content showed a decreasing trend with the increase of mowing times. The number of root neck branche and root neck diameter were better in mixed sowing than in unicast sowing. The total hay yields of WL656∶WL525=1∶4 and WL712∶WL525=1∶2 were the highest in all mixed sowing combinations, up to 14.67 t·ha-1, and the nutritive quality reached the premium alfalfa hay standard. Their annual growth was better than that of others, and it was possible to further trace the interspecific combination of research. In general, mixed sowing of alfalfa varieties with different proportions can improve forage quality and promote root growth.
Spatio-temporal variations and impacting factors of vegetation NPP in the Bosten Lake Drainage Basin from 2000 to 2014
Aizezitiyuemaier·, Maimaiti, Yusufujiang·, Rusuli, Hong Jiang, Baihetinisha·, Abudoukerimu, Hui He
2018, 12(7): 1743-1753. doi: 10.11829/j.issn.1001-0629.2017-0622
[Abstract](833) [FullText HTML] (164) [PDF 3716KB](27)
Net Primary Productivity (NPP) is an important indicator reflecting the response of terrestrial ecosystems to climate change, and is closely connected with climate change, and the carbon balance and cycle. NPP is a fundamental ecosystem function that is influenced by vegetation type, climate, and human activities at local and global scales. Research on NPP of ecosystems is important, as solutions are needed for issues, such as environmental change, sustainable management, and biodiversity conservation. Hence, an in-depth understanding of spatio-temporal variation and driving factors of NPP are fundamental for carbon balance and cycle in changing environments. Bosten Lake Drainage Basin, northwestern China, covers a vast area of complicated terrain, including the most of the middle Tianshan Mountains in the northwest, the entire Yanqi basin, and northeast Tarim basin in the south, and is characterized by distinctive distribution patterns of temperature and precipitation. In this paper, based on MOD11A2, GHCN_CAMS air temperature, DEM(digital elevation model), and metrological observed data, we established monthly Geographical Weighted Regression (GWR) models and retrieved near surface air temperature. Then, the spatio-temporal evolution characteristics and driving factors of NPP in Bosten Lake Drainage Basin was studied employing methods of slope, partial correlation, and multiple correlations as effective methodologies. The results demonstrate that: 1) the determinant coefficient (R2) of the monthly temperature GWR regression model was > 0.85 and R2 between estimated and observed air temperature was R2 > 0.9, indicating the accuracy of this research; 2) the annual mean NPP varied between 205.12~235.7 g·(m2·a)-1, whereas the inter-annual mean value was 221.52 g·(m2·a)-1. Generally, vegetation NPP in the research area showed a decreasing trend; 3) the linear slope analysis demonstrated that the NPP varied between -18~26 g·(m2·a)-1. The decreasing trend was mainly distributed in the mountains, which accounted for 5.23% of the total study area, whereas the increasing trend was mainly distributed to the oasis plain area, which accounted for 16.99%; 4) the regions with NPP changes resulted from climate factors of 39.81% of the total coverage of the research area.These regions were distributed in the mountainous and plain areas.By contrast, those subjected to non-climate factors occupied 16.57%, were mainly located at plain areas.Regarding the significance of this research, the results provide information for ecological environmental construction and sustainable development for the Bosten Lake drainage basin.
Estimation of the total production of the herbage in the Tianshan Mountain Area using remote sensing technology with NDVI similarity zoning
Yan Liu, Lei Nie, Yun Yang
2018, 12(7): 1754-1764. doi: 10.11829/j.issn.1001-0629.2018-0091
[Abstract](725) [FullText HTML] (95) [PDF 2446KB](31)
An estimation of the total production of herbage in Xinjiang using remote sensing technology is an effective method for quantitative evaluation of regional animal husbandry productivity. It is time-consuming and cannot cover the whole area of the Tianshan Mountains, although the measured accuracy of the total herbage yield using conventional means is very high. To address this problem, we used MODIS/MOD13Q1 vegetation index products, with 250 m GSD as experimental data and city or county as a basic unit for analysis. The Bhattacharyya distance was used to quantitatively evaluate the distribution of the similarity of the vegetation index in the Tianshan Mountain Area as a study case. The purpose was to obtain an effective remote sensing modeling zoning, and then to construct an estimation model of the total production of herbage with respect to the vegetation index using remote sensing technology. Finally, the spatial distribution and feature analysis of the total herbage yield (fresh weight) in the Tianshan Mountains from the year 2009 to 2015 were determined based on the analysis of the spatial distribution and characteristics obtained under the GIS platform. The results showed the following: the seven modeling zones were derived from an analysis of the mean histogram of NDVI data collected during the optimal period (i.e., July and August each year) of vegetation growth for each city or county in the study area via the Bhattacharyya distance with a threshold greater than 0.5. Secondly, the constructed estimation model of the total production of the herbage showed different fitting relationships to the vegetation index, and there were three forms, including the exponential, power index, and a unary regression equation with the second order. On the whole, the fitting correlation coefficient of the constructed estimation model could reach between 0.754 and 0.836 for each zones. The RMSE value of cross-validation in the northern slope of the Tianshan Mountains-Yili Valley was 2 951 kg·ha-1, and the RMSE value were between 266 and 928 kg·ha-1 in the other zones. This was because more measured samples which total production of the herbage was between 10 000 and 30 000 kg·ha-1 were collected in the zone. Also there was higher total production of the regional herbage in the zone than others.
Effect of grazing season and age on blood indices of sheep grazing in songnen grassland
Ying-jie Wang, Rong-zhen Zhong, Yi Fang, Zhong-yuan Zhang, Hai-xia Sun
2018, 12(7): 1765-1771. doi: 10.11829/j.issn.1001-0629.2017-0441
[Abstract](763) [FullText HTML] (56) [PDF 1292KB](14)
The seasonal change of forage is the main factor that affects the nutrition of grazing livestock, and it is necessary to systematically study the influence and extent of forage quality changes on the grazing livestock. In this experiment, we clarified the influence of seasons and ages on these indexes through a dynamic monitoring routine and estimating mineral indices of blood sampled from sheep grazing in the Songnen Grassland. The purpose of this study was to screen and assess the sensitive indicators of the nutritional status of livestock, which can provide theoretical support for the nutrition management of grazing livestock. Eight 3-month-old lambs, 3-year-old ewes, and 6-year-old ewes grazing in all four seasons were chosen for this experiment. The results show that grazing season and sheep age had significant effects on the total protein, albumin, urea nitrogen, triglyceride, and glucose content in sheep blood (P<0.05), and there was a significant interaction between age and season. The results of analysis of the major minerals in the blood showed no significant effect of age on the blood sodium content(P<0.05), but season did have a significant effect on sodium, and there was no significant effect of the interaction between age and season on blood sodium content(P>0.05). Both age and season had significant effects on potassium and chlorine in the blood, and there was a significant effect of their interaction on chlorine. Age and season significantly impacted calcium levels in the blood, but there was no effect of their interaction. Age and season, as well as their interaction, had significant effects on phosphorus levels. No significant effect of age was observed on the blood magnesium levels, but season significantly affected magnesium. In conclusion, blood urea nitrogen and phosphorus are sensitive indicators of seasonal change.
Predatory functional response of Harmonias axyridis on Megoura japonica
Jun-li Du, De-gong Wu, Bao-hong Huang, Wei-dong Huang, Zeng-xia Wang
2018, 12(7): 1772-1779. doi: 10.11829/j.issn.1001-0629.2017-0610
[Abstract](842) [FullText HTML] (115) [PDF 1517KB](18)
To clarify the predation abilities and predatory functional response of different stage of Harmonias axyridis on Megoura japonica, an experiment was conducted in an intelligent light indoor incubator operating at a temperature of (24±1) ℃, relative humidity of (70%±10%), and light∶dark cycles of 14 h∶10 h. There were significant differences between different stages of H. axyridis with respect to their daily predatory capacity on M. japonica. The predation of H. axyridis female adult and fourth instar larvae were stronger than others and their daily maximum prey capacity were 217.39 and 196.08 head·d-1, respecitiverly). They also had a lower duration of possible predation on aphids, which were 0.004 6 and 0.005 1 d, respectively. The functional responses of different stages of H. axyridis to different density of M. japonica fitted well with the Holling Ⅱ model. The searching efficiency of different stages H. axyridis decreased with increasing density of M. japonica.
Study on mixed Caragana korshinskii and maize straw silage with enzymes and their associative effects
Qi-ming Cheng, Gegentu, Kai-feng Xiang, Li-ying Liu, Wen-qiang Fan, Shu-guang Cai, Yu-shan Jia
2018, 12(7): 1780-1789. doi: 10.11829/j.issn.1001-0629.2017-0422
[Abstract](815) [FullText HTML] (65) [PDF 1357KB](25)
In order to improve the shortage of forage supply in China, we examined the variables that need to be addressed to expand the sources of foraged food. This study was designed to test two factors: the mixing ratio of Caragana korshinskii and maize straw (70∶30, 50∶50, 30∶70) and enzyme dosage (0.05%, 0.1%, 0.15%). The nutrient change, DMI, PED, and associative effects were comprehensively analyzed. The results showed: 1) The OM content of the mixed microbial silage was increased and the NDF and ADF contents of the mixed microbial silage declined significantly (P<0.05). 2) The DMI of the mixed microbial silage was significantly higher than that of the single forage without processing (P<0.05). 3) The value of PED of the nutritional indexes could be improved to a certain extent after microbial silage. Among them, the PED value of OM in the 70% C. korshinskii + 0.15% enzymes, the PED value of DM and OM in the 30% C. korshinskii + 0.05% enzymes) and the PED value of DM, OM and ADF in the 30% C. korshinskii + 0.15% enzymes were significantly higher than that of the CK1 (no microbial silage added to C. korshinskii) and CK2 (no microbial silage added to maize straw) (P<0.05). 4) By associative effects analysis, the degradation rate of DM and NDF in the rumen of 30% C. korshinskii + 0.05% enzymes showed positive associative effects and the degradation rate of DM in the rumen of 70% C. korshinskii + 0.15% enzymes and 50% C. korshinskii + 0.15% enzymes showed positive associative effects. Taking various indexes into consideration, C. korshinskii and maize mixed microbial silage can improve the nutritional value of forage and dry quality intake rate to some extent, improve the palatability of forage effectively, and improve the degradation rate of nutrients, and the optimum condition for mixed microbial silage is 30% C. korshinskii+ 70% maize straw + 0.05% enzymes.
Nutritional quality of silage made with different ratios of forage rape and corn stalks
Fa-ting Yin, Feng-hua Zhang
2018, 12(7): 1790-1796. doi: 10.11829/j.issn.1001-0629.2017-0462
[Abstract](1340) [FullText HTML] (113) [PDF 1278KB](37)
In this study, feed rapeseed harvested in the blooming stage and the corn stalk were used as raw materials and mixed-storage at different proportions to find their optimal ratio by analyzing nutrient quality. The results indicate that feed rape cannot be individually prepared for silage. After mixed-storage processing, the content of CP, EE, ADF, NDF, and Ash ranged between those of feed rapeseed and corn stalks for single storage. Nutritional quality was significantly improved and achieved the purpose of improving silage quality. The content of CP and EE in treatment Ⅲ (7∶3 rape-corn stalk ratio) was significantly higher than that in treatment Ⅳ (3∶7 rape-corn stalk ratio), while the content of ADF and NDF was significantly lower than that of treatment Ⅱ (0∶10 rape-corn stalk ratio), and treatment IV (P<0.05). The pH value of mixed storage was significantly lower than that of individual corn stalk and rape storage (P<0.05), the lowest pH value was observed in treatment Ⅲ. The score of V-Score in treatment Ⅲ (7∶3 rape-corn stalk ratio) was significantly higher than that in treatment Ⅳ (3∶7 rape-corn stalk ratio). By comprehensive comparison, we conclude that treatment Ⅲ with 7∶3 rape-corn stalk ratio should be the preferable mixing ratio.
Effect of the combination of Pennisetum sinese and sprouting corn bran on rumen fermentation characteristics
Fu-quan Yin, Zheng-min Wu, Zhi-jing Wang, Hao-hao Wu, Rui-xia Lan, Zhi-hui Zhao
2018, 12(7): 1797-1804. doi: 10.11829/j.issn.1001-0629.2017-0656
[Abstract](977) [FullText HTML] (123) [PDF 1298KB](35)
In order to understand the combined effect of Pennisetum sinese and sprouting corn bran, combinations of P. sinese and sprouting corn bran were mixed in the proportions of 100∶0, 75∶25, 50∶50, 25∶75, and 0∶100, respectively, and rumen fermentation in vitro was adopted to evaluate combination effects by analyzing total volatile fatty acids concentration, organic matter degradation rate, neutral detergent degradation rate, and acid detergent degradation rate after 24 h and 48 h. At 48 h, the degradation rate of organic matter increased significantly with increasing sprouting corn bran ratio (P<0.01). With the 0∶100 combination, the neutral detergent degradation rate was the highest and showed a significant difference (P<0.05). At 48 h, the degradation rate of acid detergent fibers in the combination group was significant higher than that in the single feed group (P<0.05). At 24 h, as the proportion of sprouting corn bran increased, acetic acid, propionic acid, and butyric acid concentrations tended to increase. At 48 h, with the combination of 25∶75, acetic acid, propionic acid, and butyric acid concentrations were the highest. Organic materials, neutral detergent fibers, and crude fibers were combined at a ratio of 75∶25 and 50∶50 to have a positive combined effect at 24 h and 48 h. The 25∶75 combination exhibited a negative combined effect. The combined effect of propionic acid and butyric acid with the 50∶50 combination was highest at 24 h and 48 h. The best combined effect of acetic acid at 24 h was seen with 75∶25 combination. In summary, combinations of P. sinese and sprouting corn bran in the range of (75∶25)~(50∶50) produced the best results.
Simulation and verification of the working process of a disc grass mower based on virtual prototyping technology
Yue-peng Song, Tao Zhang, Gui-ju Fan, Dong-sheng Gao, Zheng Wang, Xue Gao
2018, 12(7): 1805-1810. doi: 10.11829/j.issn.1001-0629.2017-0461
[Abstract](759) [FullText HTML] (55) [PDF 1647KB](21)
The virtual prototype of a disc grass cutting machine was designed by Solid Works, and its working process was simulated by ADAMS(Automatic dynamic analysis of mechanical systems) to obtain the blade rotation trajectory. The orthogonal experiment had three factors and three levels and a multi-index model was obtained. To determine the best value of the movement parameters, the comprehensive balance method was adopted.When the forward speed was 2.74 km·h-1, the rotation speed was 2000 r·min-1, the number of the blade pieces was 3, and the area of repeat cut and missed cut were effectively reduced. The motion parameters and performance index of the solid prototype were tested in the field, and the results showed that the simulation data were reliable and significant for selection of motion parameters of the disc orchard grass cutting machine.
Present situation of grass industry and countermeasures of transformational development in Dingxi
Hong-xia Wang, Zhi-dong Cao, Jin-cheng Xiang, Ping Fu
2018, 12(7): 1811-1817. doi: 10.11829/j.issn.1001-0629.2017-0051
[Abstract](855) [FullText HTML] (92) [PDF 1253KB](26)
To investigate the current status of the grass industry and existing problems, the present study examined problems that hinder transformation development in Dingxi. The problems include serious degeneration of natural grassland, low ratio of high quality varieties for artificial grass, reduced industrial processing capacity of grass products, and non-standard operation mode. Five proposals are suggested to enhance grass protection and construction to maintain regional ecological equilibrium, allow scientific planning, establish the important position of grass industry from the strategic height, increase technological innovation to enhance industrial support, recommend a modern administration system to enhance management of enterprises involved in the processing of grass products, mobilize various forces to boost industrial development, and optimize the pattern of development to enhance industrial benefits.